In XII? I cannot remember a tower with 100 floors. I do remember something incredibly similar in FFX-2, with the Via Infinito that I quite enjoyed because it was the only difficult part of the game. And in the international version of X-2, there was a tower, though fairly certain it wasn't 100 floors.

I've never owned the IZJS version of XII because the bloody Japanese never release international versions to little ol' Europe, but there might be a new dungeon in XII IZJS that I don't know about. Sorry I'm not very helpful